珠江口盆地揭阳凹陷早渐新世-中新世古生物地层及沉积环境

位于珠江口盆地揭阳凹陷的S1井是盆地东南部唯一钻井,其地层和沉积环境分析意义重大。本研究通过对S1井孢粉、有孔虫和钙质超微化石地层对比分析,确定了所钻地层时代。井段(3 326.5～2 950 m)共鉴定孢粉40属62种,孢粉组合无明显变化,以桤木粉-双束松粉为主,组合与盆地内渐新统珠海组相同。整个分析段3 326.5～2 059.5 m共鉴定浮游有孔虫11属41种,依据标准种首末现事件共划分出P19-N6 5个带或联合化石带。钙质超微化石共鉴定8属24种,划分NP23-NN4共5个钙质超微化石带。综合判定:地层时代为早渐新世-早中新世(～31-18 Ma),渐新统与中新统的界限在2 876.5 m附近。利用浮游有孔虫的丰度和底栖有孔虫的组合来判别该地层的沉积环境,认为揭阳凹陷S1井在早渐新世-早中新世均为陆坡深水环境,水深1 000 m。     

南海北部陆丰凹陷LF14-4-1D井中新世浮游有孔虫生物地层研究

通过对前人在南海北部地区的中新世浮游有孔虫生物地层研究结果的对比,发现其中分带方案有一定的差异,而且分带依据和生物事件年龄也存在争议,特别是利用岩屑样品进行地层划分与对比的钻井尤为突出,对于后续研究和南海地区的地层对比都有较大的不利影响。基于此,我们对比了前人在南海北部中新世浮游有孔虫生物地层的研究成果,结合"2012国际地质年代表"和ODP184航次提供的经天文调谐的浮游有孔虫生物事件年龄,总结了研究区中新世以浮游有孔虫生物事件末现面为基础的13个地层分带,为南海北部地区浮游有孔虫生物地层的划分与对比,特别是生产单位利用岩屑样品进行研究的钻井地层划分,提供了可供对比的基础与依据。并依据上述分带方案,将南海北部陆丰凹陷LF14-4-1D井中新世地层详细划分出早中新世至上新世期间共9个有孔虫化石带或联合带,即早中新世M3带,早-中中新世M4-6联合带,中中新世M7带,M8带,M9带,M10带,M11带,晚中新世M12带和晚中新世-早上新世M13-PL1联合带。     

海南岛近岸沉积物中的有孔虫特征与分布

对位于海南岛近岸7-170 m水深、180个站位沉积物表层样的有孔虫分析表明,研究区浮游有孔虫类型较少、共发现浮游有孔虫19种,单个站位最多含有浮游有孔虫16种,而且浮游有孔虫含量(丰度)亦较低.底栖有孔虫则较为丰富,仅在较粗砂中底栖有孔虫丰度相对较低.常见近40多个底栖有孔虫属种,多数样品中以含有螺旋式与平旋式玻璃质底栖有孔虫为主,少数样品以胶结壳、列式玻璃质壳或大型底栖有孔虫为优势特征.本研究在详细阐述了底栖有孔虫主要特征属种的基础上进行了有孔虫分区,从而揭示其所包含的环境意义.     

南海北部琼东南盆地BD-2井中新世有孔虫生物地层及沉积环境

南海北部琼东南盆地BD-2井中新世地层沉积连续,是琼东南盆地中新统较典型的钻井剖面之一。该井中新世地层中含丰富的有孔虫化石,共鉴定有孔虫62属98种,其中浮游有孔虫13属41种,底栖有孔虫49属57种。根据有孔虫标志种及螺旋浮游有孔虫旋向优势度的变化,对该井的有孔虫生物地层进行了详细划分,从早中新世至晚中新世共识别出11个有孔虫化石带或联合化石带。探讨了下中新统与中中新统,中中新统与上中新统界线的有孔虫划分标志。依据有孔虫丰度、分异度及组合特征,讨论了BD-2井从早中新世至晚中新世沉积环境演化特征。     

晚更新世南海不同海区的浮游有孔虫群落特征差异及环境控制因素

本研究对晚更新世以来(～45万)南海西部浮游有孔虫进行定量统计分析,并与南海北部和南部该时期的浮游有孔虫组合进行比较。研究发现,南海浮游有孔虫组合在以Globigerinoides ruber和Globigerinoides sacculifer为代表的热带-亚热带组合面貌为特征的背景下,其不同海区的浮游有孔虫组合具有显著差别。在南海北部,浮游有孔虫冷水型分子丰富,具有较高含量的Globorotalia inflata,Globigerina bulloides和Neogloboquadrina dutertrei等;南海西部的暖水种、冷水种含量均居中,以Globigerinita glutinata和Neogloboquadrina pachyderma高含量为特征;而南海南部则完全以具有高含量的G.ruber,G.sacculifer和Globorotalia menardii等暖水种为特征。在冰期-间冰期旋回变化中,南海北部浮游有孔虫群落面貌变化较大,南部则相对变化较小、西部变化最小。在间冰期,南海西部N.dutertrei,G.inflata,G.bulloides,G.glutinata和N.pachyderma等属种含量升高,有孔虫群落显示出上升流区特色。南海不同海区有孔虫特征属种及组合的差异,反映出有孔虫对海洋环境差异响应的敏感性,同时对海区古海洋环境研究具有参考意义。     

长江口北支兴隆沙有孔虫组合与沉积环境分析

通过对长江口北支兴隆沙XL2孔25个沉积物样品的有孔虫定量分析,发现该孔自下而上有4个有孔虫组合带(含10个有孔虫组合亚带),有孔虫分异度偏低,丰度变化大,壳径偏小,含有壳径细小的浮游有孔虫,部分壳体有机械破坏现象,这些特点反映出埋葬群在形成过程中受潮流的搬运、机械分选和破坏作用.结合沉积物粒度分析和环境磁学分析,揭示了该孔沉积环境自下而上按潮流脊-潮汐水道-潮流脊-潮坪演变的模式,进而探讨了长江口北支沉积水动力和物源.     

珠江口盆地荔湾凹陷W22井渐新世生物地层研究

通过对珠江口盆地荔湾凹陷超深水井W22井3 266～3 991 m井段72个样品开展有孔虫和钙质超微化石分析,讨论了该层段的地层划分并确定了其年代。研究层位含有丰富的有孔虫和钙质超微化石,详细的生物地层学分析显示其属于渐新世。其中,有孔虫分析发现3 390 m以下为早渐新世P18-P21a带沉积、3 380 m以上为晚渐新世P21b-P22带至N4带下部沉积,显示其地层年代为33-23 Ma;而钙质超微化石分析则揭示出该层位包含了自NP25带底部到NP21带的地层,下渐新统/上渐新统的沉积界限在3 390 m左右, Coccolithus formosus的末现面出现在3 841 m表明钻井3 841 m以深地层年代大于32.92 Ma,但更深地层未发现始新世钙质超微化石,表明底部年龄仍为早渐新世,但推测已经接近渐新世/始新世界限(33.89 Ma)。荔湾凹陷渐新世经历了从陆架浅海到上陆坡半深海环境的演变。     

中更新世撞击事件对海洋环境的影响--南海ODP1144站的高分辨率记录

本文对采自南海北部ODP1144站(20°3.18′N,117°25.14′E,水深2 037m)385.8-386.4m层段的28个沉积物样品进行了微玻陨石、浮游有孔虫及其同位素分析,以评估中更新世撞击事件对环境的影响.微玻陨石见于孔深386.12-386.38m,而集中分布在386.22-386.25m厚约3cm的地层中.研究结果表明,中更新世撞击事件对环境的影响很可能只是小幅度和短时间(百年左右)的,尽管引起了南海表层海水温度约2℃的下降及其相应的δ18O的加重、浮游有孔虫冷水种含量的上升和暖水种含量的减少,但没有造成海水稳定同位素重大偏移和全球气候的灾难性影响,也没有引起浮游有孔虫在生物演化上的变化.     

南海西沙群岛西科1井上新世有孔虫及沉积环境研究

南海西沙群岛西科1井上新世有孔虫较发育,其中浮游有孔虫Globigerinoides spp.,Orbulina universa,Globorotalia menardii和Globorotalia sp.等较丰富;Dentoglobigerina altispira,Globigerinoides quadrilobatus和Gs.trilobus等丰度较低。底栖有孔虫以大型底栖类占绝对优势,其中Amphistegina lessonii,Amphistegina madagascariensis和A.radiata等含量较高;Calcarina hispida,Cycloclypeus pillaria,Operculina bartschi和Operculina sp.等较常见;Amphistegina sp.,Anomalinoides globulosus,Cycloclypeus carpenteri,Cycloclypeus sp.,Heterostegina(Vlerkina) sp.,Homotrema sp.,Marginopora vertebralis和Planorbulinella larvata等稀少出现。小底栖类型出现少量小粟虫类和串珠虫类。根据有孔虫丰度、分异度、浮游有孔虫与底栖有孔虫比例以及环境指示类型的丰度变化,结合珊瑚、钙藻和钙质超微等化石分布特征,对上新世沉积环境演化规律进行了研究,可分为3个演化阶段:374.95～304.25 m为礁前斜坡,303.14～288.91 m为礁顶,287.47～231.86 m为礁前斜坡。通过对结壳状有孔虫形态的分析,探讨了此类有孔虫在生物礁建造中的作用。     

东印度洋赤道南北两侧春季活体浮游有孔虫的组成与分布

2017年3月通过对在东印度洋海区6个站位53个垂直分层拖网浮游有孔虫样品进行的定量分析,探讨了该海区春季现代浮游有孔虫的组成、分布及其影响因素。东印度洋春季0～3 000m水层内共鉴定出17个浮游有孔虫属种,主要是Globigerinoides ruber,Globorotaloides hexagona,Globigerinoides sacculifer,Globigerinella aequilateralis,Neogloboquadrina dutertrei,Globorotalia menardii,Globiberinella calida,Pulleniatina obliquiloculata和Globorotalia theyeri等,它们是典型的热带亚热带暖水种浮游有孔虫群落。G.ruber,G.sacculifer最大丰度层在0～50m水层;G.conglomerata,G.hexagona最大丰度层均出现在50～100m;G.theyeris在100～1 000m间的水层均有活体出现,100～150m水层中该种浮游有孔虫丰度最高;G.scitula为深层水浮游有孔虫分子,主要出现于300～2 000m的深水水层。东印度洋春季浮游有孔虫群落的丰度在赤道中心区最低,由赤道向南北两侧扩展,其丰度逐渐递增的特点。浮游有孔虫丰度明显呈上层高,下层低的特点,在50～100m水层浮游有孔虫丰度最高,明显高于0～50m水层浮游的有孔虫丰度,这与印度洋50～100m水体中叶绿素最大值层相对应,表明浮游有孔虫受水体初级生产力影响明显。     

模拟阴天对南美白对虾养殖水体理化及其生长指标的影响

为探索阴天对南美白对虾(Penaeus vannamei Boon)养殖水体理化及其生长指标的影响, 实验采用黑色遮荫网模拟阴天弱光环境对南美白对虾进行遮荫实验, 设置遮荫组与对照组各5个平行, 实验周期7周。遮荫组采用黑色遮荫网交替性遮荫, 即第1、第3、第5、第7周遮荫, 第2、第4、第6周曝光, 对照组正常养殖。结果显示: 遮荫组与对照组的pH、DO、Chl. a、 -N、NH₃-N、 -N、 -N及 -P的浓度在遮荫处理下具有显著性差异(P<0.05), Chl. a、 -N及 -P的浓度具有明显的波动性, 表现为遮荫时Chl. a的浓度极显著降低(P<0.01), -N、 -P的浓度极显著升高(P<0.01); 曝光时遮荫组Chl. a的浓度较遮荫时升高, -N的浓度极显著降低(P<0.01), -P浓度的增长幅度降低, 此时遮荫组与对照组Chl. a、 -N及 -P的浓度无显著差异。 -N的浓度在实验前5周, 遮荫组高于对照组, 第6、7周对照组高于遮荫组。 -N浓度在整个实验周期中则是遮荫组高于对照组。南美白对虾生长指标结果显示: 两个组生长指标具有显著性差异。研究表明: 妨害南美白对虾生长的主要是NH₃-N, 然后是 -N; 藻类可间接促进南美白对虾生长。遮荫处理抑制藻类吸收养殖水体中的有毒离子、恶化南美白对虾的生长环境并危害对虾的生存、生长。     

2010年夏季雷州半岛海岸带浮游植物群落结构特征及其与主要环境因子的关系

2010年夏季对雷州半岛海岸带的浮游植物群落结构及相关环境因子进行了调查,结果共检出浮游植物211种(含变种、变型),隶属于7门76属;优势种13种,以广温、广盐沿岸性种和温带沿岸性种为主,群落结构具有亚热带和沿岸性特征。半岛海岸带浮游植物平均种类数和细胞丰度的平面分布,均由近岸往远岸逐渐减少,此外种类数是西南部>西北部>南部>东南部>东北部,细胞丰度则东北部>南部>西南部>西北部>东南部。除了东北部海岸带,多样性指数和均匀度平均值分别低于3及0.7外,其他海岸带均高于此值,物种非常丰富。相关分析表明:浮游植物种类数与水温、Si/P呈极显著的正相关,与SiO23--Si、Si/N呈显著的正相关,与NO-2-N、PO34--P呈极显著的负相关,与盐度、pH值等不存在统计学意义上的相关性;浮游植物细胞丰度与pH值、叶绿素a、DO、NO-2-N呈极显著的正相关,与盐度呈极显著的负相关,与水温、NO-3-N等不存在统计学意义上的相关性;浮游植物种类数与细胞丰度之间也不存在统计学意义上的相关性。根据浮游植物生物学指标对雷州半岛海岸带的富营养化程度进行现状评价表明:雷州半岛海岸带水质营养类型属于中-贫营养型,而根据营养盐指标评价雷州半岛海岸带水质则总体上为氮限制中度营养或氮限制潜在性富营养化水平。     

Influence of nitrate and COD on phosphorus, nitrogen and dinitrotoluene (DNT) removals under batch anaerobic and anoxic conditions

In this study, the effects of COD to NO(3)-N ratio in the feed on PO(4)-P removal was investigated. Maximum PO(4)-P uptake was obtained in the anoxic reactor when the COD to NO(3)-N ratios were between 2 and 3.75. With the influent COD of 800-1500 mg COD/L a total of the maximum removable PO(4)-P was 56 mg PO(4)-P/L through 20 days of anaerobic/anoxic incubation, indicating 98% P removal in the anoxic reactor. Similarly, for the COD to NO(3)-N ratios varying between 2 and 3.75 maximum denitrification was observed. Through anoxic operation the poly-P bacteria are capable of removing NO(3)-N using VFA, COD as carbon source and NO(3)-N as the electron acceptor after methanogenesis has been completed. High NO(3)-N concentrations stopped significantly the P uptake. A total of 97-99% dinitrotoluene removal efficiencies in the reactors containing COD to NO(3)-N ratio of 2 and 3.75 after 20 days of incubation period. For maximum NO(3)-N and PO(4)-P removals optimal COD to NO(3)-N ratios, COD and NO(3)-N concentrations were 2-3.75, 2000-4000 mg COD/L and, 800-1500 mg NO(3)-N/L, respectively.     

Ammonia-nitrogen and orthophosphate removal by immobilized Scenedesmus sp. isolated from municipal wastewater for potential use in tertiary treatment

Scendesmus sp. isolated from municipal wastewater, entrapped in calcium alginate as algal sheets was employed to remove inorganic nutrients (N and P) from artificial and real domestic secondary effluents in parallel-plate bioreactor after starvation. The key factors affecting the removal efficiency (NH4+-N and PO4(3-)-P), system stability and reuse efficiency of screens were studied and discussed. It has been shown that cell density in the mixture of algal gel was the key factor compared with the thickness of the gel and the cell density of the reactor. A complete removal of NH4+-N and PO4(3-)-P was achieved within 4h of treatment in parallel bioreactors with the optimal cell density in the mixture of algal (2 x 10(8) algae mL(-1)) and 3mm gel sheets after second cycle. Nine cycles of wastewater treatment in 21 days were accomplished, holding higher removal efficiency. NH(4)(+)-N removal efficiency was 99.1% after 105 min, 100% after 135 min, PO4(3-)-P removal efficiency was 100% after 15 min in domestic secondary effluents. Immobilized Scendesmus sp. is shown to have great potentialities for removal of inorganic nitrogen and phosphorus from treated effluents.     

γ-氨基丁酸、荷包牡丹碱和L-谷氨酸钠对猫和家兔同侧和对侧图形视觉诱发电位的影响

在猫和家兔大脑半球一侧视区17/18交界处施加γ—氨基丁酸(GABA)、荷包牡丹碱和L—谷氨酸钠,以及用氯化钾和冷冻阻遏的方法,记录对侧和同侧皮层相应处图形视觉诱发电位(PVEP)的变化。讨论了GABA、荷包牡丹碱和L—谷氨酸钠对猫和兔的对侧和同侧PVEP的影响。     

Effect of carbon source on biological nutrient removal in a sequencing batch reactor

Sequencing batch operation was used for nutrient (COD, NH4-N, NO3-N, PO4-P) removal from synthetic wastewater by using different carbon sources. Operation consisted of anaerobic, anoxic, oxic, anoxic and oxic (An/Ax/Ox/Ax/Ox) phases with durations of 2/1/4.5/1.5/1.5 h. Glucose, acetate and a mixture of glucose/acetate were used as carbon source to yield a COD/N/P ratio of 100/5/1.5 in the feed. Sludge age was kept constant at 10 days. COD, NH4-N, NO3-N and PO4-P removal efficiencies were maximum at the levels of 96%, 87%, 81% and 90% respectively, when a mixture (50/50) of glucose and acetate was used.     

Two different methods of evaluating nutrient limitations of periphyton bioassays,using water from the River Rhine and eight of its tributaries

An investigation was untertaken to evaluate the nutrient status of the River Rhine (two stations) and eight of its tributaries (total of ten samplings). Determinations of the following inorganic substances were made: PO₄ ^?3-P; NO₃ ^?-N; NO₂ ^?-N; NH₄ ⁺ -N and Cl^?. In addition, pH and carbonate alkalinity were measured. Bioassays to obtain the algal growth potential (AGP) were carried out using periphyton from the River Rhine. A linear relationship could be established between NO₃ ^?-N and the AGP, while the AGP showed a non-linear dependence on the PO₄ ^3?-P concentration. The critical N/P ratio for N or P limitation of the algal growth in bioassays was evaluated graphically and by calculation. The results of the two methods are in good agreement: N is the limiting factor at NO₃ ^?N/PO₄ ^3?-P ratios less than 10, while P is limiting at ratios greater than 20. At values between 10 and 20 neither N nor P can be supposed with certainty to be limiting.     

Histone lysine methyltransferase SET7/9: formation of a water channel precedes each methyl transfer

Molecular dynamics (MD) simulations and hybrid quantum mechanics/molecular mechanics (QM/MM) calculations have been carried out in an investigation of histone lysine methyltransferase (SET7/9). Proton dissociation (SET7/9.Lys4-NH3+.AdoMet --> SET7/9.Lys4-NH2.AdoMet + H+) must be prior to the methylation by S-adenosylmethionine (AdoMet). We find that a water channel is formed to allow escape of the proton to solvent. The water channel appears in the presence of AdoMet, but is not present in the species SET7/9.Lys4-NH3+ or SET7/9.Lys4-N(Me)H2+.AdoHcy. A water channel is not formed in the ground state of SET7/9.Lys4-N(Me)H2+.AdoMet, and the second methyl transfer does not occur. The structure of SET7/9.Lys4-N(Me)H2+.AdoMet includes a greater distance (6.1 +/- 0.3 A) between Cgamma(AdoMet) and N(MeLys4) than is present in SET7/9.Lys4-NH3+.AdoMet (5.7 +/- 0.2 A). The electrostatic interactions between the positive charges on AdoMet and SET7/9.Lys4-NH3+ decrease the pKa of the latter from 10.9 +/- 0.4 to 8.2 +/- 0.6, and this is not seen in the SET7/9.Lys4-N(Me)H2+.AdoMet species. The formation, or not, of a water channel, the distance between Sdelta(AdoMet) and N(Lys4), and the angle Sdelta(AdoMet)-Cgamma(AdoMet)-N(Lys4) determine whether methyl transfer can occur. By QM/MM, the calculated free energy barrier of the methyl transfer reaction in the SET7/9 [Lys4-NH2 + AdoMet --> Lys4-N(Me)H2+ + AdoHcy] complex is DeltaG++ = 19.0 +/- 1.6 kcal/mol. This DeltaG++ is in agreement with the value of 20.9 kcal/mol calculated from the experimental rate constant (0.24 min(-1)).     

不同解磷菌处理下巨尾桉幼苗不同部位干质量及氮、磷、钾含量的变化

采用高效解磷菌P19和P7(解无机磷)以及YP17(解有机磷),研究不同浓度单一及混合解磷菌处理对巨尾桉( Eucalyptus grandis Hill ex Maiden × E. urophylla S. T. Blake)幼苗干质量、氮和钾含量的影响以及叶片磷含量的动态变化。结果表明：用5×106、2×106和1×106 CFU·mL-1解磷菌单一及混合处理后,巨尾桉幼苗的地上部分和地下部分干质量、总干质量以及氮含量总体上高于空白对照( CKB )和供磷对照( CKP ,添加18 mg·kg-1 KH2 PO4),且总体上差异显著(P<0.05),而仅少数处理组的幼苗钾含量显著高于CKB和CKP。随处理时间延长,不同解磷菌处理组的叶片磷含量呈现不同的变化趋势,但不同月份间叶片磷含量差异极显著(P<0.01);各处理组的叶片磷含量平均值均高于CKB ,且混菌处理组总体上高于单菌处理组。方差分析结果表明：不同解磷菌和不同菌液浓度对幼苗总干质量的影响效应均有显著差异;二者对幼苗氮含量有极显著或显著影响,但二者的交互作用对幼苗氮含量无显著影响(P>0.05);不同解磷菌、不同菌液浓度及二者间的交互作用对幼苗钾含量均有极显著影响;不同解磷菌、不同菌液浓度、不同时间及三者间的交互作用对叶片磷含量均有极显著影响。多重比较结果表明：P19-YP17、P7-YP17和P7-P19处理对幼苗氮含量和叶片磷含量平均值的提升作用明显,YP17、P19-YP17和P7-P19处理对幼苗总干质量平均值的提升作用明显,不同解磷菌对幼苗钾含量平均值无显著提升作用;不同菌液浓度下幼苗的总干质量、氮和钾含量以及叶片磷含量的平均值总体上显著高于CKB,其中,中浓度(2×106 CFU·mL-1)和低浓度(1×106 CFU·mL-1)菌液处理对叶片磷含量以及幼苗氮和钾含量平均值的提升作用明显。综合分析结果显示：P19-YP17、P7-YP17和P19-YP17解磷菌混合处理对巨尾桉幼苗生长有明显的促进作用,可作为混合解磷菌剂加以进一步开发研究。     

Effects of ammonia and phosphate limitation on the activated sludge treatment of calcium-containing chemical waste

Laboratory-scale biotreaters were used to study the effects of NH(3)-N and PO(4)-P nutrients on the activated sludge treatment of a chemical waste containing soluble calcium (1300 mg/L). Units receiving high or low levels of NH(3)-N and PO(4)-P were similar in their ability to remove organic compounds from the waste. Adaptation of sludges to low PO(4)-P levels (<0.1 mg/L effluent) resulted in a marked accumulation of CaCO(3) in the biosolids, whereas those receiving high PO(4)-P (2-4 mg/L effluent) had little CaCO(3). Microscopic observations of CaCO(3) containing sludges showed substantial amounts of CaCO(3) crystals imbedded in the biomass. These flocs also appeared to be enriched with nonfilamentous bacterial species in contrast to flocs devoid of CaCO(3) which had a floc structure of filamentous and nonfilamentous organisms. Scanning electron micrographs of flocs grown under low NH(3)-N showed a microbial fibrillar network of exocellular material interconnecting cells in the floc matrix. The sludges adapted to low NH(3)-N also produced higher amounts of extractable polysaccharide. CaCO(3) containing biosolids were more dense, larger, and settled better (low SVI, high ISV) than flocs devoid of the precipitates. It is not known from our experiments whether PO(4)-P or some inorganic or organic polymer produced by the floc bacteria are involved in inhibiting CaCO(3) precipitation in the activated sludge treatment of calcium-containing wastes.